Gamma-irradiation reduces survivorship, feeding behavior, and oviposition of female Aedes aegypti

Authors: Aldridge, Robert; KLINE, JEDIDIAH - Orise Fellow; COBURN, JORDAN - Department Of Defense; Gibson, Seth; BOARDMAN, LEIGH - University Of Florida; HAHN, DANIEL - University Of Florida; CHEN, CHAO - University Of Florida; Linthicum, Kenneth - Ken

Submitted to: Journal of the American Mosquito Control Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2020
Publication Date: 9/1/2020
Citation: Aldridge, R.L., Kline, J., Coburn, J.M., Britch, S.C., Boardman, L., Hahn, D.A., Chen, C., Linthicum, K. 2020. Gamma-irradiation reduces survivorship, feeding behavior, and oviposition of female Aedes aegypti. Journal of the American Mosquito Control Association. 36(3): 152–160. https://doi.org/10.2987/20-6957.1.
DOI: https://doi.org/10.2987/20-6957.1

Interpretive Summary: Aedes aegypti mosquitoes are a disease spreading mosquito that is difficult to control through traditional methods. Their behavior to live in close proximity to humans, to develop in hidden water sources, the increasing resistance to EPA approved pesticides, pesticide deregistration, and the slow production of novel pesticides further complicate control strategies. One novel method to control Ae. aegypti is the sterile insect technique (SIT) that leverages the mass release of irradiated (sterilized) males to overwhelm mate choice of females. However, one potential liability of SIT is sex sorting errors prior to irradiation resulting in accidental release of females. Our goal in this study was to test the extent to which irradiation affects female life history parameters to assess the potential impacts of releasing irradiated females accidentally sorted with males. In this study we determined that a radiation dose =30 Gy – a dose sufficient to sterilize males while preserving their virility – may substantially impact longevity, blood feeding, oviposition, and egg hatch rate of female Ae. aegypti after being irradiated as pupae. These findings could reduce public concern for accidental release of females alongside irradiated males in an operational Ae. aegypti SIT control program.

Technical Abstract: Aedes aegypti (L.) is a prominent disease-vector mosquito that is difficult to control through traditional integrated vector management due to their cryptic peridomestic immature habitat and adult resting behavior, increasing resistance to pesticide formulations approved by the US Environmental Protection Agency, escalating deregistration of approved pesticides, and slow development of new effective chemical control measures. One novel method to control Ae. aegypti is the sterile insect technique (SIT) that leverages the mass release of irradiated (sterilized) males to overwhelm mate choice of natural populations of females. However, one potential liability of SIT is sex sorting errors prior to irradiation resulting in accidental release of females. Our goal in this study was to test the extent to which irradiation affects female life history parameters to assess the potential impacts of releasing irradiated females accidentally sorted with males. In this study we determined that a radiation dose =30 Gy – a dose sufficient to sterilize males while preserving their mating competitiveness – may substantially impact longevity, bloodfeeding, oviposition, and egg hatch rate of female Ae. aegypti after being irradiated as pupae. These findings could reduce public concern for accidental release of females alongside irradiated males in an operational Ae. aegypti SIT control program.